Tuesday, April 16, 2013

North Sails H-13 Mainsail Design

Over the last 10 months North Sails have been developing a new International Moth Class mainsail for the 2013 World Championships in Hawaii.  The new design is called the H-13 model which will be in production shortly.

Testing this past week at the Moth North American Championships was very positive.  "I was for sure the fastest boat on the track by the end of the regatta and this was the first time in a long time that I have felt this good about my boat speed"  Bora Gulari

Previous designs are powerful with more return in the aft sections- the new design is aimed squarely at producing the highest Drive/Side force ratios possible with straighter aft sections and a forgiving entry angle.  

There are quite a few other significant changes as well:

-Previous Model Sails were made from a Technora Scrim with a primary focus on weight savings.  The new sail is monofilm/polyester laminate mix.  The monofilm construction is tried and proven in the Moth with good shapeholding, isotropic stretch characteristics, and of course allowing simple panel layouts for accurate shaping and smoother surfaces.  The polyester laminate in the luff sections allows for easy rigging and accurate depth/draft control in the front half of the sail.

-New luff curve allowing much higher vang tensions than previous sails.

-Elliptical roach profile lowering the center of effort and focusing area where it can be used most efficiently- IE extracting more energy from a larger wind cross-section for a fixed area. 

-The mainsail head is angled up in the leech which increases the effective span of the moth rig reducing induced drag.

-Easier Rigging with improved sleeve geometry, shaping, cam zippers and cambers with high shoulders

-Double hounds exits added to the luff sleeve

-RBS Tapered battens for more accurate tension control (less batten snaking/compression inside the pocket vs rod battens)

-Additional full batten and Cam allowing for smoother luff sleeve

Stay tuned for tuning updates and a rigging guide

For ordering information please see North Sails One Design.

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